Due to their large surface areas of up to 10 000 m2/g, MOF materials are of interest for applications in gas storage or gas separation. For most applications, it is necessary to process the pulverulent materials to compact shaped bodies. These can be handled more conveniently and especially in a safer manner, allow better exploitation of the apparatus or tank volumes and prevent large pressure drops. Prerequisites for the successful use of such shaped bodies are, however, the absorption capacity and selectivity thereof, adequate thermal and mechanical stability and high abrasion resistance. Even the recurrent thermal shocks resulting from the heat of adsorption released in the course of continuous adsorption/desorption cycles can be sufficient in the case of the related zeolite shaped bodies to cause fracture and splintering of the bodies (DE 1 905 019). Mechanical stability is therefore indispensable particularly for MOF shaped bodies which are used in vehicle tanks exposed constantly to agitation.
The general preparation of MOF pellets and extrudates is described in WO 2003/102000 and WO 2006/050898.
Kneading and/or pan milling and shaping can be carried out by any suitable method, for example as described in Ullmanns Enzyklopädie der Technischen Chemie, 4th edition, Volume 2, p. 313 ff. (1972).
Binders for the shaping of zeolites are described, for example, in WO 94/29408, EP 0 592 050, WO 94/13584, JP 03-037156 and EP 0 102 544,
MOF-containing extrudates have been reported in Chem. Eng. J. 167 (2011) 1-12. The MOF mentioned therein is based on copper and the organic compound trimesate. It is available under the commercial name Basolite C300. A report within the project DE-FC26-07NT43092 of the US Department of Energy mentions a MOF based on nickel and the organic compound 2,5-dihydroxyterephthalic acid. However, no details have been given how these extrudates could be yielded.
The relatively small number of granted patents for MOF shaped bodies underlines that current knowledge in the field is rather basic. There is a lot of room to improve this basic manufacturing technology and adapt the properties of the shaped bodies to the requirements of applications such as the storage and separation of gas. Moreover, the chemical and physical mechanisms underlying the compaction and binding of metal-organic frameworks are by far not as well understood as those of the related class of zeolites. The properties of shaped bodies resulting from the use of new additives and morphologies can hardly be predicted.